Typical aircraft today rely on a large amount of onboard electronic and computer equipment for operation of critical systems, safety, navigation, etc. For most aircraft, the space required for electronic and computer equipment tends to be substantial, and the total volume required is roughly the same regardless of aircraft size. Accordingly, onboard space is at a premium, particularly in smaller aircraft. Space in and around the cockpit of an aircraft is particularly valuable.
Moreover, today's aircraft can have literally miles of wiring for electrical systems and controls. The massive amount of wiring not only requires significant time to install in the aircraft but also contributes to the overall weight of the aircraft.